Grate shaking mechanism for fuel burning apparatus



June 18', 1940. c. H. HOLMES ET AL GRATE SHAKING MECHANISM FOR FUEL BURNING APPARATUS .Filed July 27, 1937 INVENTORS Carl jffifalmes George-1?. Gets g x m M,M

i 'atentecl June 18, 1940 UNITED GRATE SHAKING'MECHANISM roe FUEL BURNINGAPPARATUS ration of Maryland Application July 27, 1937, Serial N0. 155,846

' Claims.

This invention relates to solid fuel-burning apparatus and is for a mechanism for shaking the grates of such an apparatus. The invention is particularly applicable to hand-fired domestic heating boilers and hot air furnaces.

Solid fuel burning appliances frequently embody parallel grate bars mounted at the bottom of the combustion chamber on trunnions for oscillation about their longitudinal axes. Commonly, these gratebars are provided with depending levers, which levers are provided with pins to engage in vertical slots provided in a reciprocating grate-actuating bar. This bar is slidably supported in the base of the fuel-burning apparatus and projects through such base to the front of the furnace where it connects with a lever to which a hand lever is attached. This lever in turn is commonly pivoted on a vertically movable link or fulcrum so that when thelever is rocked back and forth a rectilinear movement will be imparted to the grate-operating bar. By reason of the engagement of the pinson the cranks depending from the grate bars in the slots of the grate-operating bar, such rectilinear movement is translated into a rocking motion of the grates. Such constructions, while commonly employed, require a great number of parts in the form of attachments, and are objectionable from the standpoint of design and appearance. Moreover, the manner of transmitting motion from the lever to the grates is ineflicient and frequently requires considerable force in operating the grates.

The present invention provides a grate-operating mechanism wherein all movable parts except the operating extension of the hand lever are located entirely within the base of the fuel-burn ing apparatus, and in which the motion of the hand lever is transmitted to the grate bars in a smooth and eflicient manner, enabling the grate bars to be operated much more easily and smoothly than in the structures heretofore provided and with less noise.

The invention also provides a more convenient arrangement than has been heretofore available for normally holding the hand lever against movement and for limiting the extent of the rocking movement of the hand lever, and which also permits the lever to be moved when de-' sired to a position where the grates can be com- Figure 1 represents a transverse vertical sec.-

(oiizs-ies) tion through the lower portion of a fuel-burning apparatus embodying ourinvention;

Figure 2 is a horizontal section in the the staggered line II'-II of Figure 1 Figure 3 is a fragmentary section'al view of the support for the rocking lever.

Referring to the drawings, 2 and 3 designate two parallel grate bars of more or less conventional form supported at the bottom of a firebox '1 in any usual or preferred way so as to rock about theirlongitudinal axes, the centers-of rotation of the grate barsbeing desiganted c. 'The grate bars themselves and the manner of supporting them in the firebox form no part of the present vinvention. any conventional arrangement being utilized. wardly' extending arm 5, which arm is provided atits lower end with a laterally offset pin or projecticn 5. While the drawings illustrate only two grate bars 2 and 3, there may be any usual number of them, depending on the size and ca pacity of the fuel-burning apparatus, twobeing the minimum number of bars employed and serving to adequately illustrate our invention. The fuel-burning apparatus is supported on an onplane of closing base structure having a rear panel 7, a.

side panel tend: a front panel 9, the front panel, of course, being provided with the usual ash door it. The projections or. trunnions Son the crank arms 5 depending from the grate bars pass through openings ii in a grate-operating bar H, the openings H. being sufficiently large to provide a free working fit. for. the projections ti therein. The forward end of thegrate-operating bar H is slop-ed downwardly, this downwardly inclined portion being designated l2, and it has a terminal portion l3? in which is a hole M Cast integrally withthefrontpanel 9 on the inside of the base are inwardly extending brackets i5 between which extends a supporting pivot Hi, this preferably also being cast integrally" with the base. The front panel 9 to the side ofthe ash door is provided with a. vertical slot-like opening ll. There is provided an external opcrating lever Ill having an offset lower portion which'projects through this slot ll, there'being a downwardly extending arm l9 on this offset portion and an integral hook-like bearing 20 that engages over the cross pin or support 6. The lower end of the arm H): has a transverse pin or projection 2| preferably formed integrally thereon, this pin projecting through the hole 14' in the terminal portion l3.of the grate-operating bar. A cotter pin 22 serves to keep the pin 2| Each grate bar is provided with a downand the end of. the: grate-operatingba'r. fromlat- 55 eral displacement. An abutment such as the projection 23 on the rear panel of the base serves to prevent lateral displacement of the grate-operating bar off the projections 6 of the crank arms 5 on the grates. Assembly of the parts as thus provided can be very simply and quickly made.

The supporting member I6 is below the level of the centers of rotation c of the rate bars 2 and 3 a distance substantially equal to the distance which the terminal of the grate-operating bar is inclined downwardly. 0 represents the centers of the pins or projections 6 on the crank arms 5. d represents the center of the bearingmember I 6 this being the center about which the lever l8 rocks. The center of theprojection 2! on the lower end of the lever is marked d. The distance between the centers (1 and d and c and c is substantially the same. Therefore, when the lever I8 is rocked on its support It, the projection H! with its pin 2! and the crank arms 5 on the grates with their projections 8 remain substantially parallel and swing through. corresponding arcs about equal radii. When the lever I8 is pulled to the left as viewed in Figure 1, the grate-operating bar ll moves to the right and also lifts upwardly. The weight of the grate-operating bar is suspended entirely from the grates and the end of the lever l8. Consequently, rocking of the lever toward the left as viewed in Figure 1, lifts the grate-operating bar II, as well as moving it to the right, which counterbalances to a considerable extent the weight of the lever. When the lever I8 is moved in the reverse direction, 1. e., toward the right as viewed in Figure l, the weight of the grate bar returning to its normal position tends to restore the grates to their normal position and again counterbalance the movement of the lever.

. The whole arrangement not only provides for a very smooth and free operation of the grates, and by reason of this counterbalancing action makes the operation of the grates easier, and less effort is required to overcome the friction between various parts than has been the case with grateoperating mechanisms heretofore provided. The

offsetting of the lower end of the lever I8 and supporting it inside the base of the fuel-burning unit-not only simplifies the general construction, but allows the grate-operating lever l8 in its normal position to stand close against the front wall of the furnace and not project out into the room as do the levers on the various grate-operating mechanisms now generally provided. This makes a more compact structure and it eliminates any requirement for a removable shaking lever such as is now generally used, because of the fact that the lever does extend so far to the front of the furnace. Moreover, the offset arrangement of the lever more effectively counterbalances the weight of the grate-operating bar I l.

The upper end of the lever l8 may have a forwardly projecting handle I8a as best shown in Figures 5 and 6, so that while the lever normally is close against the front of the furnace or boiler, it can nevertheless be very conveniently grasped.

The advantages of the invention reside, among other things, in the compactness and cheapness of the structure, its neat appearance, and in the fact that the operating lever is normally close to the front of the boiler or furnace structure, and does not project out into the room. The suspension of the grate-operating bar H from the cranks 5 and from the lower terminal of the lever lBin such mannerthat this bar has a curvilinear motion along with the lever and with the cranks on the grate bars, makes an effective linkage which is free-operating and in which the grateoperating bar H is not only effective for transmitting motion to the grate bars, but serves'also as a counterweight. The offset portion of the handle substantially closes the opening in the panel through which it extends.

While we have shown and described one specific embodiment of our invention, it will be understood that this is by way of illustration and not by way of limitation, and that various changes and modifications may be made therein.

We claim:

1. Fuel-burning apparatus comprising an enclosing structure having a base and having tiltable grates, each grate being provided with an operating crank thereon, said base having a I slotted front panel and having a bearing pin on the interior thereof adjacent the slot, an operating lever having an exposed upper portion acce sible at'the exterior of the structure and having an offset lower portion which projects through the slot and has an offset bearing intermediate the ends of the lever to engage said bearing pin, the lever having a lower terminal portion below the bearing, a grate-operating bar pivotally hung from said terminal portion of the lever and from the operating cranks on the grate, the cranks having pins thereon which pass through the bar, and an abutment on the interior of the base to prevent lateral displacement of the bar and prevent the bar from accidentally becoming disengaged from said pins.

2. Fuel-burning apparatus comprising an enclosing structure having a base and having tiltable grates, a grate-shaking lever for operating said grates, said lever having a portion which extends upwardly along the outside of the front of the structure, and having a lower portion which i normally extends downwardly inside the base, the base being slotted where the lever passes therethrough, the portion of the lever passing through the slot normally filling and closing the slot, and means on the base adjacent the slot providing a pivotal support for said lever.

3. Fuel-burning apparatus, comprising a furnace structure having a base, tiltable grates in the structure, a lever for operating the grates, said base having a slot therein, said lever having an offset portion intermediate its ends which normally closes the slot, the portion of the lever above the said offset portion normally extending upwardly generally parallel to the front of said structure, the portion of said lever below said offset portion being inside the base, and means on the inside of the base adjacent to the slot for pivotally supporting said lever.

4. Fuel-burning apparatus comprising an enclosing structure having a base, tiltable grate bars in the base having depending crank arms thereon, an operating lever pivotally supported between its ends on the base with the lowermost end of said lever inside the base and the upper portion thereof outside the base, and a grate-operating bar pivotally engaging the lower end of the lever and pivotally engaging the crank arms on the grate, the base having a vertical slot therein through which the lever passes, the lever having a diagonally offset portion positioned within the slot and normally closing the same, throughout the length and width of the slot to thereby exclude the flow of air through the slot, and whereby the portion of the lever above the 75 offset is normally close to the front of the enclosing structure.

5. Fuel burning apparatus comprising an enclosing structure having a base and having tiltable grates, a grate-shakinglever for operating said grates, said lever having a portion which extends upwardly along the outside of the front of the structure, and having a lower portion which normally extends downwardly inside the base,

the base being slotted where the lever passes therethrough, the portion of the lever passing through-the slot normally closing the slot, and means on the base adjacent the slot providing a pivotal support for said lever, the lever permitting tilting of the grates in one direction only 'from a normal position.

CARL- H. HOLMES.

GEORGE F. GEIS. 

